Biology- Chapter 17

Interphase

Time between cell division

Synthesis (S) phase

DNA is copied

Mitosis

DNA & nucleus divides; copy of original cell

Cytokinesis

Cytoplasm divides; result in 2 cells; not part of mitosis

DNA replication

Occurs in nucleus; requires enzyme

Prophase

Centrioles move to poles

Metaphase

Chromosomes line up in the middle

Anaphase

Paired chromosomes are pulled apart; now called daughter cells

Telophase

Cytokinesis begins

Cleavage furrow

The area of the cell membrane that pinches in and eventually separates the dividing cell

Meiosis

2 cells divides- half the chromosomes number; produce genetically diverse cells

Biosex males

1 parent cell= 4 sperm

Biosex females

1 parent cell= 1 functional egg & 3 nonfunctional cells

Fertilization

Sperm + Egg = Zygote = Embryo

Chromatids

Half of the duplicated chromosome

Haploid

Cell having only one complete set of chromosomes

Diploid

Two complete sets of chromosomes, one from each parent.

Random assortment

Chance distribution of chromosomes to daughter cells during meiosis

Crossing over

Homologous chromosomes exchange portions of their chromatids during meiosis

Where does meiosis occur?

Gonads (sex organs)